Im just in the process of getting my 86 pro comp ready for the water and when we tried to start it up found a small crack on one of the manifolds. We had it welded up but when we next tried to start it up found the engine was full of water to piston level.

Before I bought the boat it had been used in salt water for a number of years but flushed. Im guessing the manifolds are ready for replacing but is it possible that during the welding other cracks have opened up internally and thats how the water has got through?